Untitled

#include <iostream>
#include <cmath>
using namespace std;
int main()
{
	int y1, x1, y2, x2,x3,y3;
	float d;
	cin >> x1 >> y1 >> x2 >> y2;
	x3 = pow(x2 - x1, 2);
	y3 = pow(y2 - y1, 2);
	d = sqrt(x3 + y3);
	cout << fixed;

	cout.precision(5);

	cout << d << endl;

}